Battery charger with mechanism to automatically load and unload batteries

ABSTRACT

A mechanism is disclosed for loading/unloading one or more rechargeable batteries. The mechanism includes one or more charging compartments configured to receive one or more rechargeable batteries and a first actuator configured to cause the one or more rechargeable batteries to be displaced from a first position to a second position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 60/896,997, entitled “Battery charger with mechanism toautomatically load and eject cells” and filed on Mar. 26, 2007, thecontent of which is hereby incorporated by reference in its entirety.

BACKGROUND

Typical battery chargers require a user to insert and remove batteries(e.g., rechargeable batteries such as AA or AAA cylindrical rechargeablebatteries) manually. Proper battery orientation for such chargers isoften confusing for the user. Moreover, insertion or removal of thebatteries requires use of force that can sometimes result in accidentaldamage to the charger. Additionally, the user typically has toperiodically check connections between the charger and the battery toensure that the batteries are being properly charged. Furthermore, ifthe charger is moved or jostled during the charging operation, thecharging operation may be interrupted or otherwise stopped.

SUMMARY

In one aspect, a mechanism for loading/unloading one or morerechargeable batteries, includes one or more charging compartmentsconfigured to receive one or more rechargeable batteries and a firstactuator configured to cause the one or more rechargeable batteries tobe displaced from a first position to a second position.

In another aspect, a mechanism for loading/unloading one or morerechargeable batteries includes one or more charging compartmentsconfigured to receive one or more rechargeable batteries, an actuatorconfigured to cause at least a portion of the one or more chargingcompartments to be displaced from a first position to permit insertionor removal of a battery or batteries into or out of the one or morecharging compartments, to a second position in which a chargingoperation can be initiated.

The following are within the scope of this aspect.

The mechanism includes one or more displaceable contacts configured tobe displaced between a contact position with the one or morerechargeable batteries and a non-contact position with the one or morerechargeable batteries and a second actuator configured to cause the oneor more contacts to be displaced between the contact and the non-contactpositions. The first actuator includes a first cam mechanically coupledto a first set of one or more displaceable arms, and wherein the secondactuator includes a second cam coupled to a second set of one or moredisplaceable arms. The one or more charging compartments are inmechanical communication with the first set of one or more displaceablearms, and wherein die one or more charging compartments are configuredto be displaced in response to displacement of the first set of the oneor more displaceable arms. The first cam includes a first oblong-shapeddisc. The one or more displaceable contacts are in mechanicalcommunication with the second set of one or more arms, and wherein theone or more displaceable contacts are configured to be displaced inresponse to displacement of the second set of the one or moredisplaceable arms. The second cam includes an annular disc and a secondoblong-shaped disc disposed substantially in the space defined by theannular disc, the annular disc and the second oblong-shaped discdefining a channel configured to receive a cam follower. The mechanismincludes a motor, a spur gear, on which the first cam and the second camare mounted and a worm gear mechanically connected to the motor and inmechanical contact with the spur gear, with the worm gear configured totransfer rotational motion from the motor when the motor is operating onthe spur gear.

The first actuator and the second actuator are configured to perform anordered sequence of actuation operations. The mechanism includes acharging module configured to apply charging current to the one or moredisplaceable contacts. The mechanism includes a first limit switchconfigured to cause the motor to stop actuation when the one or morebatteries reaches the second position. The mechanism includes a secondlimit switch configured to cause the motor to stop actuation when theone or more batteries returns to the first position.

In another aspect, a charger device configured to charge one or morerechargeable batteries includes a load/unload mechanism including one ormore charging compartments configured to receive one or morerechargeable batteries a first actuator configured to cause at least aportion of the one or more charging compartments to be displaced from afirst position to permit insertion or removal of a battery or batteriesto a second position in which a charging operation can be initiated; anda controller configured to determine a current level to apply to the oneor more rechargeable batteries; and a circuit to apply the determinedcurrent level to the one or more rechargeable batteries.

The following are within the scope of this aspect.

The device includes one or more displaceable contacts configured to bedisplaced between a contact position with the one or more rechargeablebatteries and a non-contact position with the one or more rechargeablebatteries and a second actuator configured to cause the one or morecontacts to be displaced between the contact and the non-contactpositions. The first actuator includes a first cam mechanically coupledto a first set of one or more displaceable arms, and wherein the secondactuator includes a second cam coupled to a second set of one or moredisplaceable arms. The one or more charging compartments are inmechanical communication with the first set of one or more displaceablearms, and wherein the one or more charging compartments are configuredto be displaced in response to displacement of the first set of the oneor more displaceable arms. The one or more displaceable contacts are inmechanical communication with the second set of one or more arms, andwherein the one or more displaceable contacts are configured to bedisplaced in response to displacement of the second set of the one ormore displaceable arms. The device includes a motor, a spur gear, thefirst cam and the second cam being mounted on the spur gear and a wormgear mechanically connected to the motor and in mechanical contact withthe spur gear, with the worm gear configured to transfer rotationalmotion from the motor when the motor is operating on the spur gear. Thefirst actuator and the second actuator are configured to perform anordered sequence of actuation operations.

In another aspect, a mechanism for loading/unloading one or morerechargeable batteries includes one or more charging compartmentsconfigured to receive the one or more rechargeable batteries, one ormore displaceable contacts configured to be displaced between a contactposition with the one or more rechargeable batteries and a non-contactposition with the one or more rechargeable batteries, a motor, and anactuator coupled to the motor, the actuator configured to cause the oneor more contacts to be displaced between the contact and the non-contactpositions.

The following are within the scope of this aspect.

The mechanism includes a second actuator coupled to the motor, thesecond actuator configured to cause at least a portion of the one ormore charging compartments to be displaced from a first position topermit insertion or removal of a battery or batteries to a secondposition in which a charging operation is initiated.

In another aspect, a method for charging one or more rechargeablebatteries includes receiving the one or more batteries in correspondingone or more charging compartments such that the one or more batteriesare located in a first position, causing the one or more batteries to bedisplaced from the first position to a second position, determining acurrent level to apply to the one or more batteries and applying acharging current having substantially the determined current level tothe battery.

The following are within the scope of this aspect.

Causing the one or more batteries to be displaced includes actuating afirst set of displaceable arms that are in mechanical communication withthe one or more charging compartments using a first actuator. The methodincludes displacing charger contacts configured to electrically coupleto terminals of the one or more rechargeable batteries to a positionssubstantially over the one or more charging compartments. Displacingincludes actuating a second set of displaceable arms that are inmechanical communication with the charger contacts using a secondactuator.

Disclosed is a mechanism for loading and unloading batteries, such asrechargeable batteries. Also disclosed is a charger device that includessuch a mechanism for loading and unloading batteries, such a system issometimes referred to as a load/eject mechanism. In some embodiments,such a charger device is configured for fast-charge, high current,recharging applications. The disclosed mechanism and deviceautomatically load batteries into charging compartments of themechanism, commences the charging operation and unloads the batteriesupon completion of the charging operation. The mechanism adds a layer ofprotection to the user when re-charging batteries, especially batteriesthat charge at a relatively high charge rate such as Li—Fe—P batteries.With such high charge rates the charge amperage is high. By using theautomatic load/eject mechanism, 10 there is substantially less chance ofthe user coming in contact with the contacts that carry the high levelsof charging current. The mechanism can be configured to handle a varietyof battery types and configurations and allows for ease of use by aconsumer or user of the mechanism. The mechanical load/unloadingmechanism can be separate of an integral part of the charger circuits.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective front view of an exemplary embodiment of anautomatic load/unload mechanism.

FIG. 2 is a partial perspective view of the first actuator of themechanism of FIG. 1 configured to control the displacement of batteries.

FIG. 3 is a perspective back view of the mechanism of FIG. 1.

FIG. 4 is a partial perspective view of the second actuator configuredto control the displacement of charger contacts.

FIGS. 5A-B are perspective front and back views of the mechanism of FIG.1 in operation, showing batteries being placed into the charger from thetop.

FIG. 6A-B are perspective front and back views of the mechanism of FIG.1 in operation, showing the batteries being displaced into the chargingcompartments of the charger and contacts of the charger sliding over thecharging compartments.

FIGS. 7A-B are perspective front and back views of the mechanism of FIG.1 in operation, showing the batteries being displaced towards thecontacts.

FIGS. 8A-B are perspective front and back views of the mechanism of FIG.1 in operation, showing the contacts retracting inwardly to expose theopenings of the charging compartments.

FIGS. 9A-B are perspective front and back views of the mechanism of FIG.1 in operation, showing the charging compartments and the batteriesdisposed therein moving upwards to the ‘unload’ position.

FIG. 10A is a perspective view of a charger device that includes themechanism of FIG. 1, attached to a housing containing a chargingcircuit.

FIG. 10B is a perspective view of an exemplary embodiment of a chargercasing enclosing the charger device of FIG. 10A.

FIG. 11 is a block schematic of an exemplary embodiment of the chargingcircuit disposed in the housing of FIG. 10A.

FIG. 12 is a circuit schematic of the charging circuit of FIG. 11.

FIG. 13 is a flow diagram of an exemplary embodiment of operationsperformed during a charging cycle using the charger device of FIG. 10A.

DETAILED DESCRIPTION

Electrochemical cells can be primary cells or secondary cells. Primaryelectrochemical cells are meant to be discharged, e.g., to exhaustion,only once, and then discarded. Primary cells are not intended to berecharged. Primary cells are described, for example, in David Linden,Handbook of Batteries (McGraw-Hill, 2d ed. 1995). On the other hand,secondary electrochemical cells, also referred to below as rechargeablecells or batteries, can be recharged many times, e.g., fifty times, ahundred times, and so forth. Secondary cells are described, e.g., inFalk & Salkind, “Alkaline Storage Batteries”, John Wiley & Sons, Inc.1969; U.S. Pat. No. 345,124; and French Patent No. 164,681, all herebyincorporated by reference.

FIG. 1 shows an automatic load/unload mechanism 10 configured toautomatically load rechargeable batteries into charging compartments,recharge the batteries while in the charging compartments, and unloadsthe batteries upon completion of the charging operation such that thebatteries can be removed from the mechanism 10.

As shown, the mechanism 10 includes charging compartments 12 a and 12 bthat are configured to receive rechargeable batteries. In someembodiments, a device that includes an automatic load/unload mechanism,such as mechanism 10, may include only one charging compartment, or itmay include more than two charging compartments.

In the embodiments described herein, the charging compartments 12 a and12 b have a cylindrical structure configured to receive roundrechargeable AA and/or AAA batteries including, for example, batteriesbased on lithium-iron-phosphate electrochemical cells which are adapted,in some embodiments, to be recharged to at least 90% charge capacity in5-15 minutes. Other batteries based on other cell chemistries can beused including lithium-ion batteries, lead-acid, nickel metal hydride,nickel cadmium, nickel zinc, and silver zinc batteries, and so forth.The charging compartments 12 a and 12 b may be structured to receiveother mechanical configurations for the batteries, including, forexample, prismatic batteries, button-cell batteries, and so forth.

The mechanism 10 adds a layer of protection to the user when re-chargingbatteries, especially batteries that charge at a relatively high chargerate such as Li—Fe—P batteries. With such high charge rates the chargeamperage is high. By using the automatic load/eject mechanism, 10 thereis substantially less chance of the user coming in contact with thecontacts that carry the high levels of charging current.

The load/unload mechanism 10 includes an electric motor 14 that ismechanically coupled to a first actuator 16, via a back-drive resistantworm gear set that includes a disk-shaped spur gear 18 mechanicallycoupled to the electric motor 14 through a worm gear 20. The electricmotor using external AC power source providing power at a rating of,e.g., 96V-220V and 50 Hz-60 Hz, or other geographically suitable rating,a DC power supply, such as a car's DC power supply that supplies 12V DCpower, and/or batteries. Other drive mechanisms, e.g., a crank or aspring loaded mechanism, in lieu of a motor may be used. The worm gear20 is configured to rotate about its central longitudinal axis when themotor 14 is in operation, causing the spur gear 18 to rotate about itscenter. This type of arrangement is configured to have a high-reductionratio, thus resulting in high torque. This arrangement is alsoconfigured to resist back-driving motion so as to reduce or eliminatethe occurrence of unwanted motion when the motor is not in operation.

As shown, the first actuator 16 is configured to displace the batteriesand includes a cam drive having a rotateable oblong-shaped plate 22affixed to the spur gear 18 and two arms 24 a and 24 b that are securedto the charger housing or enclosure and have a single degree of freedom,i.e. to rotate up and down at respective pivot points 26 a and 26 b.When the spur gear 18 rotates, the oblong-shaped disc 22 follows therotational motion of the spur gear 18, while the arms 24 a and 24 bpivot about the pivot points 26 a and 26 b. The other two ends of thearms 24 a and 24 b are in mechanical communication with first and seconddisplaceable stages 28 a and 28 b on which the charging compartments 12a and 12 b are respectively disposed. The displaceable stage 28 a ismounted on rod rails 29 a and 29 b passing through bores defined on thedisplaceable stage 28 a. The displaceable stage 28 b is similarlymounted on rod rails 29 c and 29 d (more clearly shown in FIG. 3)passing through corresponding bores defined on the displaceable stage 28b.

As will become apparent below, rotation of the worm gear 58 and of theoblong-shaped disc 22 imparts motion, e.g., vertical motion, to the arms24 a and 24 b, causing the stages 28 a and 28 b to be verticallydisplaced along the respective rod rails on which they are mounted, thuschanging the vertical positions of the batteries received within thecharging compartments 12 a and 12 b (in some embodiments, the arms 24 aand 24 b undergo some horizontal displacement as well.)

As shown in FIG. 1, the arms 24 a and 24 b, which facilitate verticaldisplacement of the stages 28 a and 28 b have a generally horizontalorientation. Although FIG. 1 shows an embodiment in which the firstactuator 16 causes vertical displacement, in some embodiments the firstactuator may cause displacement of the batteries in other directions.For example, in some embodiments, the rechargeable batteries may beinserted from the sides such that the batteries longitudinal axis, whenreceived in the charging compartments, are oriented in a substantiallyhorizontal direction. Under those circumstances, the first actuatorcould cause horizontal displacement of the rechargeable batteries 60 aand 60 b. For a horizontal orientation, a magnet may be located in thebottom of the bores of the stages 28 a and 28 b to prevent the batteriesfrom falling out of the compartments, due to gravity or side-to-sidemovements of the charger when the batteries are exposed.

Referring to FIG. 2, showing a partial back view of the cam driveconfigured to displace the batteries, an arm end section 30 a of the arm24 a which is proximate to the pivot point 26 a, includes tire-like camfollower 32 that is in mechanical communication with the oblong-shapeddisc 22 (for the sake of clarity, the spur gear 18 has been removed fromthe view shown in FIG. 2.) As the oblong-shaped disk rotates, the camfollower 32 follows the outer edges of the oblong-shaped disk 22.Because the oblong-shaped disc 22 has a non-uniform radius, as measuredfrom its central pivot point 23 (the pivot point where the oblong-shapeddisk is affixed to the spur gear 18), as the cam follower 32 follows theouter edges of the rotating oblong-shaped disc 22, its vertical positionwill vary, causing it go up and down depending on which point on theouter edge of the oblong-shaped disc 22 the cam follower 32 is incontact with. Thus, when the oblong-shaped disc 22 is rotated so thatits tapered end 25 (which has the longest radius from the pivot point 23of the disc 22) reaches its highest position, i.e., at approximately theso-called “12-o'clock position” in the rotational path of the disc, itwill cause the cam follower 32, and the end section 30 a of the arm 24a, to be displaced to their highest positions.

As further shown in FIG. 2, attached to the other end of the arm 24 a isa rolling interface that includes a roller bearing 34 a in mechanicalcommunication with the bottom surface of the stage 28 a. The rollerbearing 34 a is configured to be displaced along the bottom surface ofthe displaceable stage 28 a. In some embodiments, the rolling interfacemay include other types of sliding mechanisms. When the disc 22 rotates,the cam follower 32 attached to end section 30 a of the arm 24 a isdisplaced, causing the arm 24 a to be displaced in both vertical andhorizontal directions. For example, when the disc 22 rotates so that thetapered end 25 of the disc 22 moves towards its top-most position, itcauses the arm 24 a to be elevated. As the arm 24 a is elevated itpushes the displaceable stage 28 a upwards via the roller bearing 34 aattached to the arm 22 a. Because the arm 24 a is pivoting about thepivot point 26 a, the elevation of the arm 24 a causes the arm 24 a toalso be displaced horizontally inwardly. The roller bearing 34 aattached to the arm 24 a thus slides along the bottom surface of thedisplaceable stage 28 a.

Referring back to FIG. 1, attached to the end section 30 a of the arm 24a is a crescent or C-shaped gear 36 a. The C-shaped gear is inmechanical communication with a symmetrically complementary C-shapedgear 36 b that is attached to an end section 30 b of the arm 24 b suchthat the respective open-ends of the gears 36 a and 36 b face inopposite directions. When the end section 30 a of the arm 24 a moves ina generally radial path, the C-shaped gear 36 a secured thereto moves inthe same direction. As a result, the motion of the C-shaped gear 36 acauses the C-shaped gear 36 b to move in a generally symmetricallyopposite radial path. For example, when the C-shaped gear 36 a moves ina generally clockwise direction, it actuates C-shaped gear 36 b to movein a generally counterclockwise direction.

The C-shaped gear 36 b is secured to the arm 24 b. Attached to the endsection of the arm 24 b underneath the displaceable stage 28 b is arolling interface that includes a roller bearing 34 b similar to theroller bearing 34 a. The roller bearing 34 b is configured to bedisplaced along the bottom surface of the displaceable stage 28 b whenthe arm 24 b is moving. Thus, when the arm 24 a is actuated to bevertically displaced via the cam follower 32, it actuates the arm 24 bto similarly be vertically displaced via the interaction between theC-shaped gears 36 a and 36 b that are attached to respective endsections of 30 a and 30 b of the arms 24 a and 24 b. Consequently, asthe arm 24 b is vertically displaced, it vertically displaces, via theroller bearing 34 b, the displaceable stage 28 b.

Referring to FIG. 3, the load/unload mechanism 10 includes a secondactuator 40 configured to control displacement of charger contacts 42 a,42 b that electrically couple to terminals of the batteries receivedwithin the charging compartments 12 a and 12 b. The charger contacts arealso electrically coupled to a charging circuit that provides a chargingcurrent applied, via the electrical contacts, to the batteries. In theembodiment shown in FIG. 3, the second actuator moves charger contacts42 a and 42 b horizontally to permit insertion of the batteries into thecharging compartments. The second actuator 40 is disposed on the side ofthe spur gear 18 that is opposite the side on which the first actuator16 is disposed. The charger contacts 42 a and 42 b are mounted on rodrails 43 a and 43 b (shown in FIG. 1) that pass through longitudinalbores located proximate the sides of the charger contacts 42 a and 42 b.The charger contacts 42 a and 42 b are thus configured to be slideablydisplaced along the rod rails 43 a and 43 b. The charger contacts 42 aand 42 b may include, for example, commercially available nickel platedcold-rolled steel spring contacts. The horizontal positions of thecharger contacts 42 a and 42 b are controlled using two arms 44 a and 44b, positioned in a general vertical orientation, that are attached tothe charger contacts 42 a and 42 b.

In the depicted embodiment for cylindrical batteries, it is understoodthat charger contacts 42 a and 42 b respectively contact, e.g., thepositive terminals of the batteries 60 a and 60 b, with the negativeterminals of those batteries contacting contacts (not shown) disposed atthe bottom of the charging compartments. On the other hand for aprismatic battery the contacts 42 a and 42 b would carry both positiveand negative contacts (not shown) and contact the correspondingterminals on the prismatic battery. Other types of prismatic batteries,which have contacts at ends of the battery, like cylindrical batteriescan be accommodated in a similar manner as the cylindrical batteries.

Referring to FIG. 4, the actuator 40 is a closed-form cam drive thatincludes an annular disc portion 46 and an oblong-shaped disc portion 48disposed substantially in the middle of the annular disc portion 46 (forthe sake of clarity, various elements of the load/unload mechanism 10,such as the spur gear 18, are not shown in the partial view of FIG. 4.)The oblong-shaped disc portion 48 is secured to the spur gear 18 suchthat when spur gear rotates, the oblong-shaped disc portion rotatesabout a pivot point 49. The oblong-shaped disc portion 48 is secured tothe spur gear 18 at the pivot point 49.

Disc portion 48 and annular disc portion 46 can be provided as onepiece. The disc portion 48 starts out as a solid. The cylindrical andoblong ‘racetrack’ grooves are machined into one side. It is shown ascut away in FIG. 4, to illustrate the follower and thus appears as twopieces in the figure. Annular disc portion 46 and the oblong-shaped discportion 48 (hereinafter annular disc 46 and the oblong-shaped disc 48)are implemented as one piece and they are joined to the spur gear 18 androtate about the pivot point 49.

The annular disc 46 and the oblong-shaped disc 48 disposed thereindefine a “race-track” channel 50. Disposed inside the race-track channel50 is a tire-like cam follower 52 that is configured to follow theoblong-shaped disc 48 inside the channel 50 as the oblong-shaped disc 48rotates. As further shown in FIG. 4, the cam follower 52 is secured tothe arm 44 a so that when the cam follower 52 is displaced by therotating oblong-shaped disc 48, the arm 44 a is horizontally displaced.The arm 44 a includes a tip 54 a that is received in a bore 56 aextending from the bottom surface of the charger contact 42 a. When thearm 44 a is actuated by the oblong-shaped disc 48 acting on the camfollower 52, the arm 44 a is displaced horizontally (the arm 44 a alsoundergoes some vertical displacement) and thus causes the chargercontact 42 a to slide horizontally along the rail rods 43 a and 43 b.

Referring back to FIG. 3, the arms 44 a and 44 b are attached to eachother through a push-pull rod 57. Thus, the displacement of the arm 44a, through actuation by the oblong-shaped disc 48 acting on the camfollower 52, causes the arm 44 b to be displaced. For example, when thearm 44 a is actuated to be horizontally outwardly displaced, the arm 44b is actuated, through the push-pull rod 57, to be horizontallyoutwardly displaced in the opposite direction.

As will become apparent below, in some embodiments, the first and secondactuators are configured to implement a mechanical timing mechanism thatcauses displacement of the respective arms coupled to the actuators in aparticular order. Particularly, in some embodiments, the second actuator40 is configured such that, for example, the arms 44 a and 44 b are notdisplaced into a closed position over the received batteries until afterthe first actuator 16 has caused the arms 24 a and 24 b to displace thedisplaceable stages 28 a and 28 b to their low position. In other words,the actuators 16 and 40 cause displacement of the respective arms theyactuate at different times, thus enabling an ordered sequence ofoperations in which batteries are lowered, and the charger contacts 42 aand 42 b are then displaced over the lowered batteries. After thecharging operation is completed, the second actuator 40 causes thecharger contacts to open, and the first actuator 16 subsequentlyelevates the displaceable stages 28 a and 28 b to enable removal of thethus charged batteries.

In some embodiments, this type of ordered sequence of operations may beimplemented by aligning the respective oblong-shaped discs of theactuators 16 and 40 so that their tapered ends are in different radialpositions (i.e., they are out of phase with respect to each other).Thus, when the spur gear 18, to which both the oblong-shaped discs 22and 48 are secured, begins to rotate, one oblong-shaped, e.g., disc 22,will cause actuation of the arms 24 a and 24 b, while, at the same time,the other rotating oblong-shaped disc 48 is traveling in a radialsection of its path in which it does not cause significant displacementof the arms it operates on. Configuring the actuators 16 and 40 toimplement a mechanical timing mechanism reduces of the likelihood ofaccidental arms malfunction due to, for example, entanglements of therespective arms actuated by the actuators 16 and 40.

FIGS. 5-9 show the load/unload, mechanism 10 in operation.

Referring to FIGS. 5A and 5B, two batteries 60 a and 60 b are insertedinto the charging compartments 12 a and 12 b, respectively. In thebattery-load position, the oblong-shaped disc 22 (shown in FIG. 5A) isoriented so that the tapered end 25 is substantially at the top-mostposition of its rotational path. Thus, the arms 24 a and 24 b, actuatedby the disc 22 via the cam follower 32, secured to the arm end 30 a andthe C-shaped gears 36 a and 36 b, are extended such that stages 28 a and28 b are at their top-most positions.

As shown in FIG. 5B, the oblong-shaped disc 48 of the actuator 40 isoriented so that the tapered end of the disc 48 is substantially at the10-o'clock position of its rotational path such that the end section ofthe arms 44 a and 44 b secured to the battery covers 42 a and 42 b arein their inwards most position, thus allowing the covers to convergesubstantially in the middle of the rails 43 a and 43 b, thus opening thecharging compartments to received the batteries 60 a and 60 b. As shown,the respective tapered ends of the oblong-shaped discs 22 and 48 are indifferent radial positions along the rotational paths that the discsfollow, which enables the mechanism 10 to implement an ordered actuationsequence as will become apparent.

Referring to FIGS. 6A and 6B, upon initiation of the charge cycle (e.g.,by a user pressing, a ‘START’ button located, for example, on theexternal casing of the charger device in which the load/unload mechanismis disposed, or by a controller module responding to a sensor indicationthat batteries have been received in the charging compartments), theelectric motor 14 begins to operate causing the worm gear 20 and thespur gear 18 to rotate. The spur gear rotates clockwise (as viewed fromthe front view of FIG. 6A whereas, the oblong-shaped disc 22 secured tothe spur gear 18 rotates to a radial position in which the tapered end25 of the disc 22 is approximately 45° from the bottom-most position ofits radial path (i.e., the tapered end is at the approximate ‘4-o'clock’position of its radial path). At that position, the cam follower 32attached to arm end section 30 of the arm 24 a will have been actuatedto a position in which it will be in mechanical contact with a sectionof the disc 22 that is proximate to the wide end of the disc 22. Pointsat or near the wide end of the oblong-shaped disc 22 have shorter radiito pivot point 23 of the disc 22 compared to the radius measured fromthe tapered end 25 of the disc. Thus, the cam follower 32 will besubstantially at the bottom-most position it can attain, andconsequently, the arm 24 a will have been actuated to its lowestvertical position. Additionally, the C-shaped gear 36 a attached to thearm 24 a will have rotated clockwise, thus causing the C-shaped gear 36b, attached to the arm 24 b, to be rotated counter-clockwise, thusactuating the arm 24 b to its lowest vertical position. As a result, thestages 28 a and 28 b will have been displaced to their lowest verticalposition, thus causing the batteries 60 a and 60 b received within thecharging compartments 12 a and 12 b to be lowered.

Referring to FIG. 6B, showing the back view of the load/unload mechanismshown in FIG. 6A, the cam driver 40, which includes the ‘race-track’channel 50 defined by the oblong-shaped disc 48 and the annular disc 46,is oriented so that the tapered end of the oblong-shaped disc 48 and ofthe channel 50 is substantially at the ‘3-o'clock’ position of therotational path of the oblong-shaped disc 48. At that position, thecam-follower 52 attached to the arm 44 a will be at its farthestposition from the pivot point 23, and thus will have actuated the arm 44a to its outward-most horizontal position. As a result, the chargercontacts 42 a will be at its outward-most horizontal position, where itis placed substantially above the charging compartment 12 a. Actuationof the arm 44 a to its outward-most horizontal, position will actuatethe arm 44 b, through the push-pull rod 57, to its outward-mosthorizontal position, and thus the charger contact 42 b will be at aposition substantially above the charging compartment 12 b.

When the batteries 60 a and 60 b have been lowered to their lowestposition, they will generally be out of view.

In some embodiments, the load/unload mechanism 10 is configured to avoidexcessive side loading of the battery/contact interface. Specifically,the actuator used to control the vertical displacement of the stages 28a and 28 b actuates the arms 24 a and 24 b to slightly displace thestages 28 a and 28 b upwards after the charger contacts 42 a and 42 bhave been displaced to a position above the charging compartment 12 aand 12 b.

Referring to FIG. 7A, the oblong-shaped disc 22 rotates further in aclockwise direction to a position in which the tapered end 25 of thedisc 22 is substantially at its lowest-most position (i.e.,substantially the ‘6-o'clock’ position.) At that position, the camfollower 32 will have been actuated to a vertical position that isslightly higher than the position attained when the tapered end 25 ofthe oblong-shaped disc 22 was substantially at the ‘4-o'clock’ position,and likewise the arm 24 a will also be actuated to a vertical positionhigher than it had when the tapered end 25 was at the ‘4-o'clock’position.

Referring to FIG. 7B, the rotation of cam driver 40 controlling thehorizontal displacement of the charger contacts 42 a and 42 b will causeminor changes in horizontal displacement of the covers 42 a and 42 b,but the battery covers will generally remain substantially above thecharging compartments 12 a and 12 b. The covers 42 a and 42 b arestationary above the batteries when they move upward to make contact.

As the batteries rise to make electrical and mechanical contact with thecontacts 42 a and 42 b, the rim of the charging compartment 12 b willcome in contact with a ‘charge position’ electromechanical limit switch58 b that is secured to a tab 59 b extending from the side of thebattery cover 42 b (see also FIG. 1.) The mechanical contact between therising charging compartment 12 b and the limit switch 58 b will causethe limit switch 58 b to produce a signal that is provided eitherdirectly to the motor 14, or to a controller 80 (shown in FIG. 11), thatis configured to control the motor 14, including causing the motor 14 tostop its operation, and thus cease actuation of the stages 28 a and 28 band of the charger contacts 42 a and 42 b. When the motor 14 has ceasedits operation the charging procedure, described in greater detail below,is commenced.

Referring to FIG. 8A, after the charging procedure has been completed,the motor 14 is re-started, for example, by having the controller 80send control signals to cause the motor 14 to resume its operation. Theoblong-shaped disc 22 resumes its rotation and actuates the cam follower32, and thus the arm 24 a, to cause the stages 28 a and 28 b to beslightly displaced vertically downwards.

The oblong-shaped disc 22 rotates to a position in which its tapered end25 is between the ‘9-o'clock’ and ‘10-o'clock’ radial position, in whichthe cam follower 32 is resting at a vertical position that is lower thanthat at which the cam follower 32 was when the tapered end 25 of thedisc 22 was at the 6-o'clock position. Consequently, the stages 28 and28 b, as well as the batteries 60 a and 60 b will be moved to a lowervertical position than when charging was performed, as indicated by thearrows 61 a and 61 b. By lowering the stages 28 a and 28 b, and thuslowering the batteries 60 a and 60 b, the batteries terminals disengagefrom the contacts 42 a and 42 b, thus enabling the contacts 42 a and 42b to retract from their position over the charging compartments 12 and12 b without being damaged.

Referring to FIG. 8B, resuming the operation of the motor 14 also causescam driver 40 to resume its rotation, thus causing actuation of the arms44 a and 44 b, via the cam follower 50 a secured thereto, to an inwardhorizontal position.

During the actuation of the arms 44 a and 44 b, the cam follower 32follows the edges of the oblong-shaped disc 22 as the disc 22 istraveling through a portion of its radial path that does not result insignificant vertical displacement of the cam follower 32, and thereforedoes not result in a significant vertical displacement of the stages 28a and 28 b. Consequently, the stages 28 a and 28 b will undergo most oftheir upwards vertical displacement after the charger contacts 42 a and42 n have been substantially retracted to approximately the center ofthe rod rails 43 a and 43 b.

Referring to FIGS. 9A and 9B, when the charger contacts 42 a and 42 bhave substantially fully retracted to the center of the rod rails 43 aand 43 b, the batteries 60 a and 60 b are actuated to move upward to theremoval position. As shown, the oblong-shape disc 22 completes itsradial path and returns to the position in which the tapered end 25 ofthe disc 22 is at its top-most position (i.e., substantially at the12-o'clock position). As a result, the cam follower 32 will be atsubstantially the farthest point from the pivot point 29 of theoblong-shaped disc 22, and consequently, the arms 24 a and 24 b willhave been actuated to their upwards-most vertical displacement, causingthe stages 28 a and 28 b to be elevated, and the batteries 60 a and 60 bto be exposed. When the oblong-shaped disc 22 reaches the radialposition in which the tapered end 25 is at the 12-o'clock position, an‘unload’ limit switch 58 a is engaged and the motor is stopped.

As shown in FIG. 9A, the unload switch 58 a is mounted in the upperright hand corner of the mechanism as viewed in FIG. 9A. A plate 59 amounts the ‘eject’ switch to the contact 42 a. A threaded rod 59 b ismounted to the bottom of the stage 28 a which depresses (actuates) theswitch 58 a when batteries reach the eject position. The rod 59 b andthe switch 58 a come in proximity to each other when the contacts 42 aand 42 b are in the centered position and the battery stages 28 a and 28b are in the ‘eject’ or ‘unload’ position.

Referring to FIGS. 10A and 10B, a battery charger device 70 thatincludes the automatic load/unload mechanism 10 is shown. The charger 70includes a housing 72 in which a charging circuit (not shown in FIGS.10A-B) is disposed. The charging circuit is electrically coupled to thecontacts 42 a and 42 b. When the displaceable covers 42 a and 42 b areactuated to a position above the charging compartments 12 a and 12 b andcome in electrical communication with the terminals of the batteries 60a and 60 b received inside the charging compartments 12 a and 12 b, thecharging circuit causes the charging operation to commence.

As shown in FIG. 10B, the battery charger device 70 is enclosed incharger casing 71. The casing 71 includes openings 73 a and 73 bleading, respectively, into the charging compartments 12 a and 12 b. Auser places batteries, such as batteries 60 a and 60 b, through theopenings 73 a and 73 b.

In some embodiments, the charger 70 is configured to charge arechargeable battery to at least 90% of the battery's charge capacity inless than 15 minutes. In some embodiments, the charger 70 achieves acharge of at least 90% in approximately five (5) minutes. Other chargingprofiles are possible.

FIG. 11 depicts an exemplary embodiment of the charging circuit charger72. The charging circuit 72 is configured to initially apply a constantcharging current to the rechargeable batteries, such as the batteries 60a and 60 b, received in one of the charging compartments 12 a of theload/unload mechanism 10. During the period in which a constant currentis delivered to the battery (during this period the charger is said tobe operating in constant current, or CC mode), the voltage of thebattery 60 a increases. When the voltage of the battery reaches apre-determined upper limit voltage of, for example, 3.8V (this upperlimit voltage is sometimes referred to as the crossover voltage), thecharging circuit 72 is configured to apply to the battery 60 a, for theremainder of the charging period, a voltage having this value. Duringthe period that a constant voltage, substantially equal to thepre-determined crossover value, is applied to the battery 60 a, thecharging circuit 72 is said to be operating in constant voltage, or CV,mode.

The charging circuit 72 is coupled to a power conversion module 74. Thepower conversion module 74 includes an AC/DC converter 76 that iselectrically coupled to an AC power source, external to the charger,such as a source providing power at a rating of 85V-265V and 50 Hz-60Hz, and converts the AC power to a low D.C. voltage (e.g., 5-24V) ande.g., feeds this low D.C. voltage to, e.g., a DC-DC converter 78 toprovide a level suitable for charging rechargeable batteries (e.g., DCvoltages at levels of approximately between 3.7-4.2V for therechargeable batteries having lithium-iron-phosphate electrochemicalcell. Other types of cells may have different voltage levels.)

The charging circuit 72 includes a controller 80 that is configured todetermine the charging current to be applied to the batteries 60 a and60 b, apply to the batteries 60 a and 60 b a current substantially equalto the determined charging current, and terminate the charging currentafter a specified or pre-determined time period has elapsed. Thecontroller 80 may also be configured to terminate the charging currentonce a pre-determined battery voltage or charge level has been reached.In some embodiments, the controller 80 regulates a buck converter 90 toapply a constant 12 C charge rate (i.e., a charge rate of 1 Ccorresponds to the current that would be required to charge a battery inone hours, and thus 12 C is a charge rate that would to charge theparticular battery in approximately 1/12 of an hour, i.e., fiveminutes.) Such a charge rate of 12 C is applied until a predeterminedmaximum charge voltage is reached, or a period of five (5) minutes hasexpired. Once the maximum charge voltage is reached, the controller 80changes control modes and applies a constant voltage to the batteries 60a and 60 b, until the pre-determined charge time has expired, e.g., 5minutes.

In some embodiments, determination of the charging current to be appliedto the batteries 60 a and 60 b may be based, at least in part, on userspecified input provided through a user interface disposed, for example,on the casing 71 of the charger 70. Such a user interface may include,for example, switches, buttons and/or knobs through which a user mayindicate, for example, the capacity of the of battery that is to berecharged. Additionally, in some embodiments, the interface may beconfigured to enable the user to specify other parameters germane to thecharging process, such as, for example, the charging period (incircumstances where a longer charging period, e.g., 15 minutes to 1hour, is desired.) To determine the specific charging current to use, alookup table that indexes suitable charging currents corresponding tothe user-specified parameters is accessed.

In some embodiments, determination of the charging current may beperformed by identifying the capacity of the battery(s) placed in thecharging compartment of the charger 70 using, for example, anidentification, mechanism that provides data representative of thebattery capacity and/or battery type. A detailed description of anexemplary charger device that includes an identification mechanism basedon the use of an ID resistor having a resistance representative of thebattery's capacity is provided in the concurrently filed patentapplication entitled “Ultra Fast Battery Charger with Battery Sensing”,the content of which is hereby incorporated by reference in itsentirety. In some embodiments, determination of the charging current maybe performed by measuring at least one of the battery's electriccharacteristics indicative of the capacity and/or type of battery (e.g.,the battery's charging resistance.) A detailed description of anexemplary charger device that adaptively determines the charging currentbased on measured characteristics of the battery is provided in theconcurrently filed patent application entitled “Adaptive Charger Deviceand Method”, the content of which is hereby incorporated by reference inits entirety.

The controller 80 includes a processor device 82 configured to controlthe charging operations performed on the batteries 60 a and 60 b. Theprocessor device 82 may be any type of computing and/or processingdevice, such as a PIC18F1320 microcontroller from Microchip TechnologyInc. The processor device 82 used in the implementation of thecontroller 80 includes volatile and/or non-volatile memory elementsconfigured to store software containing computer instructions to enablegeneral operations of the processor-based device, as well asimplementation programs to perform charging operations on the batteries60 a and 60 b coupled to the charger 70, including such chargingoperations that achieve at least 90% charge capacity in less thanfifteen (15) minutes. The processor device 82 includes ananalog-to-digital (A/D) converter 84 with multiple analog and digitalinput and output lines. The controller 80 also includes adigital-to-analog (D/A) converter device 86, and/or a pulse-widthmodulator (PWM) 88 that receives digital signals generated by theprocessor device 82 and generates in response electrical signals thatregulate the duty cycle of switching circuitry, such as the buckconverter 90 of the charging circuit 72.

FIG. 12 shows the buck converter 90 including two, e.g., Bi-PolarJunction Transistors (BJT's) 92 and 94 and an inductor 96 that storesenergy when the power conversion module 74 is in electricalcommunication with the buck converter 90, and which discharges thatenergy as current during periods that the power conversion module 74 iselectrically isolated from the buck converter 90 (for the sake ofsimplicity, the circuit schematic shows only the battery 60 a.) The buckconverter 90 shown in FIG. 12 also includes a capacitor 98 that is alsoused as an energy storage element. The inductor 96 and the capacitor 98also act as output filters to reduce the switching current and voltageripples at the output of the buck converter 90. Operation of a buckconverter, such as the buck converter 90 shown in FIG. 12, is moreparticularly described in, for example, concurrently filed applications“Fast Battery Charger Device and Method,” the content of which is herebyincorporated by reference in its entirety.

The transistor's on-period, or duty cycle, is initially ramped up from0% duty cycle, while the controller or feedback loop measures the outputcurrent and voltage. Once the determined charging current is reached,the feedback control loop manages the transistor duty cycle using aclosed loop linear feedback scheme, e.g., using aproportional-integral-differential, or PID, mechanism. A similar controlmechanism may be used to control the transistor's duty cycle once thecharger voltage output, or battery terminal voltage, reaches thecrossover voltage.

Thus, the current provided by the power conversion module 74 during theon-period of the transistor 92, and the current provided by the inductor96 and/or the capacitor 98 during the off-periods of the transistor 92should result in an effective current substantially equal to therequired charging current.

In some embodiments, the controller 80 periodically receives (e.g.,every 0.1 second) a measurement of the current flowing through thebatteries 60 a and 60 b as measured, for example, by a current sensorthat communicates the measured value in one or both batteries via aterminal 80 c (marked ISENSE) of the controller 80. Based on thisreceived measured current, the controller 80 adjusts the duty cycle tocause an adjustment to the current flowing through the batteries 60 aand 60 b so that that current converges to a value substantially equalto the charging current level. The buck converter 90 is thus configuredto operate with, an adjustable duty cycle that results in adjustablecurrent levels being supplied to the batteries 60 a and 60 b.

In addition to the voltage sensor and/or the current sensor, the charger70 may include other sensors configured to measure other attributes ofeither the batteries 60 a and 60 b and/or the charger 70. For example,in embodiments in which thermal control of the charger 70 is required(e.g., for charger that have a charging period of more than 15 minutes),the charger 70 may include temperature sensors (e.g., thermistors)coupled to the batteries 60 a and 60 b and/or to a circuit board onwhich the charging circuit 72 may be disposed.

FIG. 13 depicts an exemplary charging procedure 100 to recharge therechargeable batteries 60 a and 60 b. The batteries 60 a and 60 b areplaced through the openings 73 a and 73 b on the casing 71 enclosing themechanism 10 and the circuit housing 72. The user may then initiate thecharging cycle by pressing a ‘START’ button disposed on the casing 71.In some embodiments, a sensing mechanism may detect that batteries havebeen placed in the charging compartment and thus may initiate thecharging cycle automatically.

With the charging cycle initiated, the motor 14 begins operation, andcauses actuation of the actuator that controls the displacement of thestages 28 a and 28 b to displace, 102, the batteries 60 a and 60 b froma first position (i.e., the receiving position) to a second position(i.e., the charging position) in which a charging current is to beapplied. In the exemplary embodiment described herein, the motor 14causes rotation of a cam driver 16 that includes the oblong-shaped disc22, which in turn actuates the arms 24 a and 24 b, via the cam follower32, to displaced the stages 28 a and 28 b into the interior of themechanism 10. The operation of the motor 14 also causes rotation of asecond actuator 40 to actuate the arms 44 a and 44 b to displace thecharger contacts 42 a and 42 b over the batteries 60 a and 60 a so thatthe contacts 42 a and 42 b contact the terminals of the batteries 60 aand 60 b.

Alter the batteries 60 a and 60 b have been displaced to their chargeposition, the ‘charge position’ limit switch 58 a causes operation ofthe motor 14 to cease, thus halting the displacement of the stages 28 aand 28 b, and of the charger contacts 42 a and 42 b.

With the batteries now in their charge position, and the batteries'terminals in electrical communications with the electrical contacts ofthe contacts 42 a and 42 b, the charging process may proceed.Optionally, prior to commencing the charging procedure, the charger 70determines whether certain fault conditions exist. For example, thecharger 70 measures 104 the voltage V_(a) and V_(b) of the batteries 60a and 60 b, respectively. The charger 70 determines 106, whether themeasured voltages are within a predetermined range (e.g., between2-3.8V.) In circumstances in which it is determined that the measuredvoltages, V_(a) and V_(b), of either of the batteries 60 a and 60 b arenot within the predetermined acceptable ranges, thus rendering acharging operation under current conditions to be unsafe, the chargerdoes not proceed with the charging operation, and the charging processmay terminate. Under these circumstances, the batteries are unloaded120, as described herein.

The charger 70 determines 108 a charging current and/or a chargingperiod to be used to charge the batteries 60 a and 60 b based oninformation germane to the charging process, including the type ofbatteries, the charging period, the batteries' capacity, etc. Forexample, the charger 70 may be configured to determine a chargingcurrent to charge the batteries 60 a and 60 b to at least a 90% chargecapacity in less than 15 minutes. In some embodiments, charging currentsuitable for longer charging periods (e.g., 1-4 hours), differentbattery capacities, and different charge levels, may be determined.

The information used to determine the charging current may be providedthrough a user interface disposed, for example, on the casing 71 of thecharger 70. Additionally and/or alternatively, such information may beprovided through an identification mechanism through which thebatteries, for example, can communicate to the charger informationrepresentative of their characteristics (e.g., capacity, type.) In someembodiments, determination of the charging current to apply may be basedon information obtained by measuring electrical characteristics of thebatteries (e.g., charging resistance), and determining, based on suchmeasurements, the type and/or capacity of the batteries 60 a and 60 b.If the charger 70 is configured to receive a particular type of batteryhaving a particular type of capacity, the charger 70 uses apre-determined charging current suitable for that particular battery andcapacity. Determination of the charging current may be performed byaccessing a lookup table that associates charging currents withdifferent battery capacities, battery type, charging periods, etc.

Having determined the charging current to be applied to batteries 60 aand 60 b, a timer, configured to measure the pre-specified time periodof the charging operation, is started 110. The timer may be, forexample, a dedicated timer module of the processor 84, or it may be acounter that is incremented at regular time intervals measured by aninternal or external clock of the processor 84.

A current/voltage regulating circuit, such as, for example, the buckconverter 90 shown in FIG. 12, is controlled 112 to cause a constantcurrent substantially equal to the determined current to be applied tothe rechargeable batteries 60 a and 60 b. As explained, the chargingcurrent determined is used to generate a duty cycle signal, applied, forexample, to the transistor 92 of the buck converter 90, to cause currentsubstantially equal to the charging current to be applied to the battery12. Thus, the controller's output signals are applied, for example, tothe transistor 92 of the buck converter 90 to cause voltage from thepower conversion module 74 to be applied to the batteries 60 a and 60 b.During the off-time of a particular duty cycle, the power conversionmodule 74 is cutoff from the batteries 60 a and 60 b, and the energystored in the inductor 96 and/or capacitor 98 is discharged to thebatteries as a current. The combined current applied from the powerconversion module 74, and the current discharged from the inductor 96and/or the capacitor 98 result in an effective current substantiallyequal to the determined charging current.

In some embodiments, the charger 70 implements a CC/CV charging process.Thus, in such embodiments, the voltage at the terminals of the batteries60 a and 60 b is periodically measured 114 (e.g., every 0.1 seconds) todetermine when the pre-determined upper voltage limit (i.e., thecrossover voltage) has been reached. When the voltage at the terminalsof the batteries 60 a and 60 b has reached the pre-determined uppervoltage limit, e.g., 4.2V, the current/voltage regulating circuit iscontrolled 116 (e.g., through electrical actuation of the transistors 92and 94) to have a constant voltage level substantially equal to thecrossover voltage level maintained at the terminals of the batteries 60a and 60 b.

After a period of time substantially equal to the charging time periodhas elapsed, as determined 118, or after a certain charge or voltagelevel has been reached (as may be determined through periodicalmeasurements of the batteries 60 a and 60 b) the charging currentapplied to the batteries 60 a and 60 b is terminated (for example, byceasing electrical actuation of the transistor 92 to cause powerdelivered from the power conversion module 74 to be terminated).

The batteries 60 a and 60 b can be removed 120 from the charger byresuming operation of the motor 14. Operation of the motor 14 causes thespur gear 18 to resume rotation, thus causing the cam drivers 16 and 40to actuate the respective arms that they act upon. In the orderedsequence of operations implemented by the two actuators, the cam driver16, which includes the rotating oblong-shaped disc 22, actuates the arms24 a and 24 b to slightly displace the batteries to enable the chargercontacts 42 a and 42 b to begin retracting from the position over thecharging compartments 12 a and 12 b without being damaged. The camdriver 40, which includes the oblong-shaped disc 48 and the annular disc46 that together define the race-track channel 50, actuate the arms 44 aand 44 b to retract the charger contacts 42 a and 42 b to substantiallythe center of the rod rails 43 a and 43 b. The rotating oblong-shapeddisc 22 actuates the arms 24 a and 24 b to displace the stages 28 a and28 b and thus move the batteries 60 a and 60 b to their unload position.At that point the ‘unload’ limit switch is engaged and operation of themotor 14 ceases and the batteries 60 a and 60 can be removed by a user.

Additional exemplary embodiments charging circuits and chargingprocedures are described, for example, in the concurrently filed patentapplications entitled “Fast Battery Charger Device and Method” and“Lithium Iron Phosphate Ultra Fast Battery Charger”, the contents of allof which are hereby incorporated by reference in their entireties.

OTHER EMBODIMENTS

A number of embodiments of the invention have been described. Forexample the charging compartments can include a movable base portion andfixed, e.g., cylindrical sidewalls, in which the movable base portion isactuated by the mechanism 10 to displace the battery between first andsecond positions, while the sidewalk of the charging compartments remainstationary. Nevertheless, it will be understood that variousmodifications may be made without departing from the spirit and scope ofthe invention. Accordingly, other embodiments are within the scope ofthe following claims.

1. A mechanism for loading/unloading one or more rechargeable batteries,the mechanism comprising: one or more charging compartments configuredto receive one or more rechargeable batteries; a first actuatorconfigured to cause at least a portion of the one or more chargingcompartments to be displaced from a first position to permit insertionor removal of a battery or batteries into or out of the one or morecharging compartments, to a second position in which a chargingoperation can be initiated; one or more displaceable contacts configuredto be displaced between a contact position with the one or morerechargeable batteries and a non-contact position with the one or morerechargeable batteries; and a second actuator configured to cause theone or more contacts to be displaced between the contact and thenon-contact positions.
 2. The mechanism of claim 1, wherein the firstactuator includes a first cam mechanically coupled to a first set of oneor more displaceable arms, and wherein the second actuator includes asecond cam coupled to a second set of one or more displaceable arms. 3.The mechanism of claim 2, wherein the one or more charging compartmentsare in mechanical communication with the first set of one or moredisplaceable arms, and wherein the one or more charging compartments areconfigured to be displaced in response to displacement of the first setof the one or more displaceable arms.
 4. The mechanism of claim 2,wherein the first cam includes a first oblong-shaped disc.
 5. Themechanism claim 2, wherein the one or more displaceable contacts are inmechanical communication with the second set of one or more arms, andwherein the one or more displaceable contacts are configured to bedisplaced in response to displacement of the second set of the one ormore displaceable arms.
 6. The mechanism of claim 2, wherein the secondcam includes an annular disc and a second oblong-shaped disc disposedsubstantially in the space defined by the annular disc, the annular discand the second oblong-shaped disc defining a channel configured toreceive a cam follower.
 7. The mechanism of claim 2, further comprising:a motor; a spur gear, on which the first cam and the second cam aremounted; and a worm gear mechanically connected to the motor and inmechanical contact with the spur gear, with the worm gear configured totransfer rotational motion from the motor when the motor is operating onthe spur gear.
 8. The mechanism of claim 1, wherein the first actuatorand the second actuator are configured to perform an ordered sequence ofactuation operations.
 9. The mechanism of claim 1, further comprising: acharging module configured to apply charging current to the one or moredisplaceable contacts.
 10. The mechanism of claim 7, further comprising:a first limit switch configured to cause the motor to stop actuationwhen the one or more batteries reaches the second position.
 11. Themechanism of claim 7, further comprising: a second limit switchconfigured to cause the motor to stop actuation when the one or morebatteries returns to the first position.
 12. A charger device configuredto charge one or more rechargeable batteries, the device comprising: aload/unload mechanism comprising: one or more charging compartmentsconfigured to receive one or more rechargeable batteries; and a firstactuator configured to cause at least a portion of the one or morecharging compartments to be displaced from a first position to permitinsertion or removal of a battery or batteries to a second position inwhich a charging operation can be initiated; and a controller configuredto: determine a current level to apply to the one or more rechargeablebatteries; and a circuit to apply the determined current level to theone or more rechargeable batteries.
 13. The device of claim 12, furthercomprising: one or more displaceable contacts configured to be displacedbetween a contact position with the one or more rechargeable batteriesand a non-contact position with the one or more rechargeable batteries;and a second actuator configured to cause the one or more contacts to bedisplaced between the contact and the non-contact positions.
 14. Thedevice of claim 13, wherein the first actuator includes a first cammechanically coupled to a first set of one or more displaceable arms,and wherein the second actuator includes a second cam coupled to asecond set of one or more displaceable arms.
 15. The device of claim 14,wherein one or more charging compartments are in mechanicalcommunication with the first set of one or more displaceable arms, andwherein the one or more charging compartments are configured to bedisplaced in response to displacement of the first set of the one ormore displaceable arms.
 16. The device claim 14, wherein the one or moredisplaceable contacts are in mechanical communication with the secondset of one or more arms, and wherein the one or more displaceablecontacts are configured to be displaced in response to displacement ofthe second set of the one or more displaceable arms.
 17. The device ofclaim 14, further comprising: a motor; a spur gear, the first cam andthe second cam being mounted on the spur gear; and a worm gearmechanically connected to the motor and in mechanical contact with thespur gear, with the worm gear configured to transfer rotational motionfrom the motor when the motor is operating on the spur gear.
 18. Thedevice of claim 13, wherein the first actuator and the second actuatorare configured to perform an ordered sequence of actuation operations.19. A mechanism for loading/unloading one or more rechargeablebatteries, the mechanism comprising: one or more charging compartmentsconfigured to receive the one or more rechargeable batteries; one ormore displaceable contacts configured to be displaced between a contactposition with the one or more rechargeable batteries and a non-contactposition with the one or more rechargeable batteries; a motor; and anactuator coupled to the motor, the actuator configured to cause the oneor more contacts to be displaced between the contact and the non-contactpositions.
 20. The mechanism of claim 19, further comprising: a secondactuator coupled to the motor, the second actuator configured to causeat least a portion of the one or more charging compartments to bedisplaced from a first position to permit insertion or removal of abattery or batteries to a second position in which a charging operationis initiated.
 21. A method for charging one or more rechargeablebatteries, the method comprising: receiving the one or more batteries incorresponding one or more charging compartments such that the one ormore batteries are located in a first position; causing the one or morebatteries to be displaced from the first position to a second position,with causing the one or more batteries to be displaced further includes:actuating a first set of displaceable arms that are in mechanicalcommunication with the one or more charging compartments using a firstactuator; determining a current level to apply to the one or morebatteries; and applying a charging current having substantially thedetermined current level to the battery.
 22. The method of claim 21,further comprising displacing charger contacts configured toelectrically couple to terminals of the one or more rechargeablebatteries to a position substantially over the one or more chargingcompartments.
 23. The method of claim 22, wherein displacing the chargercontacts comprises: actuating a second set of displaceable arms that arein mechanical communication with the charger contacts using a secondactuator.